# 2.1: Customary Units of Length

**At Grade**Created by: CK-12

**Practice**Customary Units of Length

Have you ever planted a garden? Have you ever looked at a package of seeds to see how tall a plant would grow or how far you should plant them apart?

Well, Tania is going to plant a vegetable garden with her brother Alex. Tania is going to start the plants as seedlings and then transfer them outside.

To get started, Tania does a little research about starting tomatoes. On the package, she reads that she should plant each seed 1/4" deep and 1/2" apart. Then she notices that the next instruction says that she should cover the seeds so that they are 1/4" deep.

Tania takes out her ruler and gets started.

**To be successful in her task, Tania will need to know how to measure length in customary units. Pay attention during this Concept and you will learn how to help Tania.**

### Guidance

** Measurement** is a concept that appears all the time in everyday life. How far apart are two houses? How long is a basketball court? How far is the Earth from the sun? Sometimes we need to measure a long distance and sometimes we need to measure very short distances. You have probably measured many things before in your life.

If we measure ** length**, we measure the distance between two points, two things or two places. For the tomato plant question, we want to measure how long something is. To measure length, we need to use a unit of measure.

**Let’s begin by learning about the** *Customary Units***of measurement for measuring length.**

The most common Customary Units of measurement are the inch, the foot, the yard and the mile.

The inch is the smallest of these units of measurement. There are 12 inches in 1 foot. There are 3 feet in 1 yard. There are 5,280 feet in 1 mile. Whew! That is a lot of measuring. Let’s go back to the inch and work with that one first.

**Inches**

One ** inch** is roughly the length of your thumb from the tip to the knuckle. The ruler below is shows inch long segments (not shown to actual scale).

We can measure small things in inches. That is what makes the most sense. Here is a picture of a crayon. Let’s look at how long the crayon is in inches.

We can also divide up the inch. An inch can be divided into smaller units. We can divide the inch into quarters. Look at this ruler. We can see \begin{align*}\frac{1}{4}”, \frac{1}{2}”, \frac{3}{4}”\end{align*}.

Beyond that, we can measure things as small as eighths. This means that each inch can be divided into 8 units. Two times this smallest unit is one fourth of an inch. Let’s look at what one fourth of an inch looks like on a ruler.

**We use inches and parts of inches to measure small items.**

**Feet**

The next unit we use is the ** foot**. To abbreviate the foot we write \begin{align*}ft\end{align*} (for example, 3 ft). One foot is roughly the length from your elbow to the end of your fingers. We can use a ruler to measure feet, because a ruler is exactly one foot long.

As you can see, one foot is much longer than one inch. We therefore use feet to measure bigger objects, such as the height of a door or the length of a car. We can also use feet to measure the distance between things. When two people stand apart, it would take a lot of inches to measure the distance between them. In this case, we can use feet.

**Yards**

A unit of measurement that you will sometimes hear about is ** yards.** There are three feet in one yard. You can think about yards as being a measurement shortcut.

The rope was 2 yards long. **How long was the rope in feet?** Well, you can think about this mathematically. If the rope was 2 yards long and there are 3 feet in every yard then we can multiply to figure out the number of feet that the rope is.

3 \begin{align*}\times\end{align*} 2 \begin{align*}=\end{align*} 6

**The rope is 6 feet long.**

It makes sense to use inches, feet and yards when measuring short distances or the length of objects or people. We use these customary units of measurement all the time in our everyday life.

**What happens when we want to measure long distances-like the distance between two houses or two cities?** It would be very complicated to use feet or yards to figure this out.

In a case like this, we use our largest customary unit of length-*the mile.*

**Miles**

There are 5,280 feet in one mile. The best thing for you to remember about miles right now is that miles are used to measure very long distances.

Here are few things for you to measure in inches. Find examples of these things and measure them.

#### Example A

Pencil

**Solution: Answers will vary. Check your measurement with a peer.**

#### Example B

Your Sneaker

**Solution: Answers will vary. Check your answers with a peer.**

#### Example C

Your math notebook

**Solution: Answers will vary. Check your answers with a peer.**

Now let's think about Tania and her tomato plants. Here is the original problem once again.

Tania is going to plant a vegetable garden with her brother Alex. Tania is going to start the plants as seedlings and then transfer them outside.

To get started, Tania does a little research about starting tomatoes. On the package, she reads that she should plant each seed 1/4" deep and 1/2" apart. Then she notices that the next instruction says that she should cover the seeds so that they are 1/4" deep.

Tania takes out her ruler and gets started.

This problem doesn't exactly ask you to figure something out. However, you should now understand that how to find each of the measurements for the tomatoes on a ruler. Look at the following ruler and identify where 1/4" and where 1/2" are located. Then you are ready to move on in the Concept.

### Vocabulary

Here are the vocabulary words for this Concept.

- Measurement
- using different units to figure out the weight, height, length or size of different things.

- Length
- how long an item is

- Customary units of length
- units of measurement such as inches, feet, yards and miles

- Inches
- the smallest customary units of measurement, measured best by a ruler

- Foot
- a customary unit of measurement, there are 12 inches in 1 foot

- Yard
- a customary unit of measurement, there are 3 feet in 1 yard

- Mile
- a customary unit for measuring distances, there are 5280 feet in 1 mile

### Guided Practice

Here is one for you to try on your own.

Kyle is going to help his mother put a fence up in their yard. If he is going to be measuring the distance between fence posts and the height of the fence, which measurement unit will Kyle need to work accurately?

**Answer**

Inches will be too small for Kyle, and it doesn't make sense to use miles. Kyle will need to use feet as he works on the fence.

### Video Review

Here is a video for review.

Khan Academy Adding Different Units of Length

### Practice

Directions: Write the appropriate customary unit of measurement for each item.

1. The height of a sunflower

2. The depth to plant a seed in the soil

3. The height of a tree

4. The area of a garden plot

5. The distance from a garden to the local farm store

6. The length of a carrot

7. A stretch of fencing

8. The length of a hoe

9. The distance between two seedlings planted in the ground

10. The height of a corn stalk

11. A piece of pipe for a water line

12. The depth of a pool

13. The distance across a lake

14. The distance from your home to school

15. The size of a paperclip

16. The measure of a length of thread

Customary System

The customary system is the measurement system commonly used in the United States, including: feet, inches, pounds, cups, gallons, etc.Customary units of length

Customary units of length include: inches, feet, yards and miles.Foot

A foot is a customary unit of measurement. There are 12 inches in 1 foot.Inches

An inch is a customary unit of measurement, measured best by a ruler.Length

Length is a measurement of how long something is. Examples of customary units of length are inches, feet, yards and miles.Measurement

A measurement is the weight, height, length or size of something.Mile

A mile is a customary unit for measuring distance. There are 5280 feet in 1 mile.Yard

A yard is a customary unit of measurement. There are 3 feet in 1 yard.### Image Attributions

Here you'll learn how to measure length in customary units.

## Concept Nodes:

Customary System

The customary system is the measurement system commonly used in the United States, including: feet, inches, pounds, cups, gallons, etc.Customary units of length

Customary units of length include: inches, feet, yards and miles.Foot

A foot is a customary unit of measurement. There are 12 inches in 1 foot.Inches

An inch is a customary unit of measurement, measured best by a ruler.Length

Length is a measurement of how long something is. Examples of customary units of length are inches, feet, yards and miles.Measurement

A measurement is the weight, height, length or size of something.Mile

A mile is a customary unit for measuring distance. There are 5280 feet in 1 mile.Yard

A yard is a customary unit of measurement. There are 3 feet in 1 yard.